In the Garden:Coastal and Tropical South
January, 2009
Regional Report

Packed Pots

A great joy of container gardening is filling -- and refilling -- an ever-growing collection with plants of all sorts. But how much space do those additions really need to thrive? That depends on the factors of what, where, and why. Ask yourself: 1) what kind of plants are already there and what do you want to add, 2) where do you have room to add, and 3) why are some add-ons a better bet than others?

Making Good Fits
When someone gifts you with a bag of freesia bulbs, it's a simple matter to slip their little selves into any nook and cranny. The gift of a softball-size swamp spider bulb needs more attention to be sure it won't crowd other plants, but it can be a nearly evergreen centerpiece of a 2-foot planter box with night-blooming jasmine at its side.

A huge pot with a shrub at its center is one thing, and a container of perennials is another. While the former looks okay all year, the latter is a sad sight at times. You can prevent that "dead container" specter with succession planting. In that case, let one plant replace another and/or succeed it in taking center stage. For instance, deciduous daylilies leave a pot barren in winter unless daffodils or muscari are interplanted with them. They die back just as the daylilies return. Big perennials can be replaced by annuals and bulbs to fill in the weeks or months when the perennials are dormant. Once you cut down the Amazon dianthus, periwinkle and caladium fill the space until cool weather revives the "big pinks."

How Big is Big
It may look like there's not enough space for anything else in that pot, but think again. Seasonal color annuals don't need much root room to make a big show above ground, many bulbs even less. And combinations can keep the pot blooming most all year long. A very upright pot of nandina can stand alone, but a skirt of 'Million Bells' calibrachoa softens its lines. Several feet of trailing trumpets fall from one small plant with no more than a 3-inch root ball. This and similar plants fit right in at the foot of such shrubs. If companion planting is one of your organic practices, slip a pest-repelling garlic clove into every pot that contains a rose. Even huge perennials like cannas are much wider across their tops than at their base, leaving space for other annuals or smaller perennials.

Best Choices
Perennials with opposite season interest but similar needs make for companionable growing. Hosta can fill pots with summer flowers, with Lenten rose added for winter interest in similar light conditions. Consider plants with approximately equivalent water needs. Drought tolerance is a quality shared by succulent plants like sedums, jade plant, and flax. Adding such stalwarts to a pot of philodendron will result in overwatering the succulents, likely killing them. And unless you are a completely organic gardener, it's a wise idea to grow vegetables together, but not with ornamental plants that might need pesticide sprays not labeled for food plants. Start with a collection of pots and choose plants that suit their style, each other's needs, and your tastes. You'll soon have a garden that is uniquely your own, and always has room for one more plant.